Micromagnetic modeling, as a progressive numerical simulation method of magnetic research, can reveal the magnetization mechanism of materials while saving experimental costs. However, its application scale is limited by the enormous computational cost. Currently, micromagnetic simulations are mainly applied to calculate the magnetization of nanocrystalline magnets below the micrometer level. For larger magnets with grain sizes in the range of tens micrometers, such as sintered Nd-Fe-B magnets, this high-precision numerical calculation method may be less effective. To end this, this study proposes a nanocrystal-sized micromagnetic model, which is adjusted by fitting the magnetization relaxation time and intergranular coupling strength. Through incorporating time and spatial correction coefficients, it can calculate the magnetization behavior of large-grain magnets effectively. The thermal demagnetization process of sintered Nd-Fe-B magnets is further analyzed, and the micromagnetic simulation results are compared with the experimental results from temperature-controlled demagnetization experiments, which confirms the accuracy of the equivalent method. This research expands the research application scale of micromagnetic simulations and reveals the magnetization mechanism of sintered Nd-Fe-B magnets under thermal effects.

中文翻译：

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考虑时空校正的 NdFeB 微磁模拟

微磁建模作为磁学研究的一种先进数值模拟方法，可以揭示材料的磁化机理，同时节省实验成本。然而，其应用规模受到巨大的计算成本的限制。目前，微磁模拟主要用于计算微米级以下纳米晶磁体的磁化强度。对于晶粒尺寸在数十微米范围内的较大磁体，例如烧结Nd-Fe-B磁体，这种高精度数值计算方法可能效果较差。为此，本研究提出了一种纳米晶尺寸的微磁模型，通过拟合磁化弛豫时间和晶间耦合强度来调整该模型。通过结合时间和空间校正系数，可以有效计算大晶粒磁体的磁化行为。进一步分析了烧结Nd-Fe-B磁体的热退磁过程，并将微磁模拟结果与温控退磁实验结果进行了比较，证实了等效方法的准确性。该研究拓展了微磁模拟的研究应用规模，揭示了烧结Nd-Fe-B磁体在热效应下的磁化机理。